• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8B
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• pp.730-737
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• 2003

In this paper, we present an efficient authentication proxy for IEEE 802.1x systems based on the port-based access control mechanism. An IEEE 802.1x system consists of PC supplicants, a bridge with authentication client functions, and an authentication server. For the network security and user authentication purposes, a supplicant who wants to access Internet should be authorized to access the bridge port using the Extended Authentication Protocol (EAP) over LAN. The frame of EAP over LAN is then relayed to the authentication server by the bridge. After several transactions between the supplicant and the server via the bridge, the supplicant may be either authorized or not. Noting that the transactions between the relaying bridge and the server will be increased as the number of supplicants grows in public networks, we propose a scheme for reducing the transactions by employing an authentication proxy function at the bridge. The proxy is allowed to cache the supplicant's user ID and password during his first transaction with the server. For the next authentication procedure of the same supplicant, the proxy function of the bridge handles the authentication transactions using its cache on behalf of the authentication server. Since the main authentication server handles only the first authentication transaction of each supplicant, the processing load of the server can be reduced. Also, the authentication transaction delay experienced by a supplicant can be decreased compared with the conventional 802.1x system.

• Journal of Pharmacopuncture
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• v.18 no.1
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• pp.36-43
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• 2015

Objectives: Water-soluble carthami flos (WCF) is a new mixture of Carthami flos (CF) pharmacopuncture. We conducted a 4-week toxicity test of repeated intramuscular injections of WCF in Sprague-Dawley rats. Methods: Forty male and 40 female rats were divided into 4 groups of 10 male and 10 female SD rats: The control group received 0.5 mL/animal/day of normal saline whereas the three experimental groups received WCF at doses of 0.125, 0.25, and 0.5 mL/animal/day, respectively. For 4 weeks, the solutions were injected into the femoral muscle of the rats alternating from side to side. Clinical signs, body weights, and food consumption were observed; opthalmological examinations and urinalyses were performed. On day 29, blood samples were taken for hematological and clinical chemistry analyses. Then, necropsy was conducted in all animals to observe weights and external and histopathological changes in the bodily organs. All data were tested using a statistical analysis system (SAS). Results: No deaths were observed. Temporary irregular respiration was observed in male rats of the experimental group for the first 10 days. Body weights, food consumptions, opthalmological examinations, urinalyses, clinical chemistry analyses, organ weights and necropsy produced no findings with toxicological meaning. In the hematological analysis, delay of prothrombin time (PT) was observed in male rats of the 0.25- and the 0.5-mL/animal/day groups. In the histopathological test, a dose-dependent inflammatory cell infiltration into the fascia and panniculitis in perimuscular tissues was observed in all animals of the experimental groups. However, those symptoms were limited to local injection points. No toxicological meanings, except localized changes, were noted. Conclusion: WCF solution has no significant toxicological meaning, but does produce localized symptoms. No observed adverse effect level (NOAEL) of WCF in male and female rats is expected for doses over 0.5 mL/animal/day.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.1
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• pp.123-133
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• 2018

Cyber-Physical System (CPS) is a system in which a physical system and a cyber system are strongly integrated. In order to operate the target physical system stably, the CPS constantly monitors the physical system through the sensor and performs control using the actuator according to the current state. If a malicious attacker performs a forgery attack on the measured values of the sensors in order to conceal their attacks, the cyber system operated based on the collected data can not recognize the current operation status of the physical system. This causes the delay of the response of the automation system and the operator, and then more damage will occur. To protect the CPS from increasingly sophisticated and targeted attacks, countermeasures must be developed that can detect stealthy deception attacks. However, in the CPS environment composed of various heterogeneous devices, the process of analyzing and demonstrating the vulnerability to actual field devices requires a lot of time. Therefore, in this study, we propose a method of constructing the experiment environment of the PLCitM (PLC in the middle) which can verify the performance of the techniques to detect the CPS stealthy deception attack and present the experimental results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.243-250
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• 2016

The body composition and arterial compliance with advanced age increase the risks of cardiovascular diseases, but the elderly can perform rhythm exercise easily, which may positively influence their body composition and arterial compliance. Therefore, this study examined the effects of rhythm exercise training on the body composition and arterial compliance in elderly females. The subjects (n=20) were assigned randomly to either an exercise group (n=10, EX) or non-exercise control group (n=10, CON). The rhythm exercise training for 12 weeks consisted of 3 sessions per week with 60 minutes per session. In addition, the intensity was set to 11-14 of the Borg scale (6-20). The body composition and arterial compliance (pulse wave velocity (PWV)) were measured before and after training. The skeletal muscle mass in the EX was increased significantly (p=0.04) and the right (p=0.002) and left side (p=0.02) of the PWV in the EX were decreased significantly, but the skeletal muscle and both sides of the PWV in the CON were not changed. Elderly females could easily perform rhythm exercise training, which resulted in improvements of the skeletal muscle mass and arterial compliance. Therefore, rhythm exercise training may prevent or delay sarcopenia and reduce the risk of cardiovascular diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2451-2458
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• 2010

We prepared sustained release matrix system which contains carvedilol with Compritol 888 ATO used as lipophilic sustained release excipient and hydroxypropyl methyl cellulose (HPMC) or polyethylene oxide (PEO) used as hydrophilic sustained release polymer. Wet granulation compressed method was used for preparing carvedilol sustained release matrix tablets. When carvedilol sustained release matrix tablets were prepared, we evaluated the drug release kinetics which is affected by Compritol 888 ATO ratio, a kind of hydrophilic polymer (HPMC, PEO) and hot melt coating coagglutination (HMCC) process was done. The drug release kinetics was measured for 24 hours in pH 1.2 simulated gastric fluid and pH 6.8 simulated intestinal fluid, using a dissolution tester at $37.5^{\circ}C$ in 50 rpm. Dissolution rate of controlled release matrix tablets of carvedilol was evaluated by paddle method. We confirmed that HMCC process was very effective to controlled release of drugs. The rate of Compritol 888 ATO, as a lipidic material, can control the drug release pattern about the elution rate of 95% and 24 hours delay than that of the normal tablet.

• Journal of KIISE:Information Networking
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• v.29 no.4
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• pp.447-458
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• 2002

In this paper, we design and implement Wireless Transaction Protocol(WTP) and evaluate it for wireless transaction processing in mobile computing environments. The design and implementation of WTP are based on the coroutine model that might be suitable for light-weight portable devices. We test the compatibility between our product and the other products such as Nokia, Kannel and WinWAP For the evaluation of WTP, we use an Internet simulator that can arbitrary generate random wireless errors based on the Gilbert model. In our experiment, the performance of WTP is measured and compared to those of Transmission Control Protocol(TCP) and TCP for Transactions. The experiment shows that WTP outperforms the other two protocols for wireless transaction processing in terms of throughput and delay. Especially, WTP shows much higher performance In ease of high error rate and high probability of burst errors. This comes from the fact that WTP uses a small number of packets to process a transaction compared to the other two protocols and introduces a fixed time interval for retransmission instead of the exponential backoff algorithm. The experiment also shows that the WTP performance is optimized when the retransmission counter is set to 5 or 6 in case of high burst error rate.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.2
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• pp.47-56
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• 2015

In an energy saving server cluster environment, the power modes of servers are controlled according to load situation, that is, by making ON only minimum number of servers needed to handle current load while making the other servers OFF. This algorithm works well under normal circumstances, but does not guarantee QoS under abnormal circumstances such as sharply rising or falling loads. This is because the number of ON servers cannot be increased immediately due to the time delay for servers to turn ON from OFF. In this paper, we propose a new prediction algorithm of the power consumption for improving QoS under not only normal but also abnormal circumstances. The proposed prediction algorithm consists of two parts: prediction based on the conventional time series analysis and prediction adjustment based on trend analysis. We performed experiments using 15 PCs and compared performance for 4 types of conventional time series based prediction methods and their modified methods with our prediction algorithm. Experimental results show that Exponential Smoothing with Trend Adjusted (ESTA) and its modified ESTA (MESTA) proposed in this paper are outperforming among 4 types of prediction methods in terms of normalized QoS and number of good reponses per power consumed, and QoS of MESTA proposed in this paper is 7.5% and 3.3% better than that of conventional ESTA for artificial load pattern and real load pattern, respectively.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.74-77
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• 1996

This experiment was conducted to evaluated the effect of CM (plant growth regulator) treatment on flowering, pod maturing and root yield components of Astragalus membramaceus Bunge. Three dilution rates (60, 70 and 80 times) were sprayed at $3{\sim}4$ leave stage. As the results, flowering was delayed $25{\sim}35$ days than August 13 of control and higher dilution rates was more effective to delay flowering. At the havesting time, be compared with non-treatment, plant height reduced $7.6{\sim}18.9\;cm$ and number of matured pods were decreased $50.6{\sim}76.1$ by increasing dilution rates. However, weight of dry root per plant was increased to 29% and dry root yield per 10a was increased to 28% in dilution rates 70 compared with non-treatment.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.173-181
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• 2004

To delay the onset of apoptosis in the culture, transformed Tn 5B1-4 cells harboring anti-apoptotic genes, bcl-2 and baculovirus p35, have been established and analyzed for their anti-apoptotic ability in suspension culture using spinner flasks. In the suspension culture at agitation speeds of 100 rpm and 200 rpm, the cell growth of cell clone expressing Bcl-2 protein was much higher than other two clones and the maximum cell density of the clone was 6.0 ${\times}$ 10$^{6}$ cells/ml and 6.2 ${\times}$ 10$^{6}$ cells/ml at day three of the incubation. On the other hand, the cell growth of cell clone expressing baculovirus protein P35 was much higher than other two clones in suspension culture at agitation speed of 300 rpm and the maximum cell density of the clone was 6.1 ${\times}$ 10$^{6}$ cells/ml at day three of the incubation. Based on the pattern of genomic DNA laddering and the microscopic observation of apoptotic bodies, the more apoptotic bodies are induced in Tn 5B1-4 control cell clone at higher agitation speed. This result shows that the shear stress can be a main factor in inducing apoptosis in spinner flask culture. At low agitation speed, cell clone expressing Bcl-2 was more effective in delaying the onset of apoptosis than the cell clone expressing P35. On the other hand, at high agitation speed, cell clones expressing baculovirus P35 was more effective in delaying the onset of apoptosis than the cell clone expressing Bcl-2. Therefore, anti-apoptotic genes, bcl-2 and baculovirus p35, can playa distinct role depending on agitation speed in the suspension culture.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.341-346
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• 2014

This study was conducted to evaluate the effect of trehalose on the rheological properties of bread flour dough. Farinographic and viscographic properties, pH, total titratable acidity (TTA), and fermentation power were analyzed for flour dough rheology. Flour dough containing trehalose showed greater water absorption capacity and longer development time. However the stability, degree of softening, and farinograph quality number (FQN) were lower for the trehalose-containing flour dough, however, these factors decreased with increasing amounts of trehalose. Trehalose did not affect the beginning of gelatinization temperature and maximum viscosity temperature of flour. The maximum viscosity was the lowest with 6% trehalose, the end of final holding period, breakdown and setback values decreased with increasing amounts of trehalose. Flour dough with 4% trehalose had the lowest pH value for 120 min fermentation at $30^{\circ}C$, and the highest TTA value. Addition of 4% and 6% trehalose showed larger fermentation volume of dough than the control. The results suggested that trehalose positively affected the rheological properties of flour dough such as bread volume, softness, and staling delay.